Asymmetric information distribution systems are characterized by high capacity or high bandwidth downstream (i.e., server to client) communication channels and low capacity or low bandwidth upstream (i.e., client to server) communication channels. In several communications systems the data to be transmitted is compressed so that the available bandwidth is used more efficiently. For example, the Moving Pictures Experts Group (MPEG) has promulgated several standards relating to digital data delivery systems. The first, known as MPEG-1 refers to ISO/IEC standards 11172 and is incorporated herein by reference. The second, known as MPEG-2, refers to ISO/IEC standards 13818 and is incorporated herein by reference. A compressed digital video system is described in the Advanced Television Systems Committee (ATSC) digital television standard document A/53, and is incorporated herein by reference.
Unfortunately, present asymmetric information distribution systems and, more particularly, data transfer protocol methodologies utilized by such systems, do not provide a sufficiently flexible solution to implementing a multiple information service (e.g., VOD, data network access, voice and the like) information distribution system.
To facilitate client-server interaction in an asymmetric information distribution system, especially an asymmetric information distribution system offering the such multiple information services, it is seen to be desirable to provide a data transfer protocol that allows flexible resource allocation, efficient data transfer and control operations and scalability.